将Java中的Arraylist中的字符串拆分为substring个字母

Question

我有两个类 Reader 和 Tokenizer。 我想在标记器 class 中从 Reader class 中拆分 Wlist Arraylist 中的字符串。必须根据字符串的奇数和偶数长度进行拆分。

例如：如果字符串是“teacher”，由于它的长度是奇数，它应该被分成三部分“te”、“ac”、“her”。

如果 string 甚至像“cattle”，它应该被分成 3 个部分“ca”、“tt”、“le”。

读者 Class

import java.util.ArrayList;
import java.util.List;

public class Reader {

    String[] wordList = {"Printer", "Airport", "Painter", "Letter",
                         "vehicle", "Teacher"};

    String[] SentenceList = {"Device made to waste ink and paper","Platform for Commercial air transport",
                             "Someone who uses colors and brushes","a written type of communication sent by mail",
                             "Thing used to travel via land","A person who teaches"};

    ArrayList<String> Wlist = new ArrayList<>(6);
    public ArrayList<String> wordCheck(){

        for(int i=0;i<6;i++){
            if((wordList[i] != null) && (!wordList[i].equals("")) && (wordList[i].matches("^[a-zA-Z]*$"))
                    && (wordList[i].length()>4)) {
                //System.out.println("Array does satisfy the required criteria");
                Wlist.add(wordList[i].toUpperCase());
            }
            else
            {
                System.out.println("Array does NOT satisfy the required criteria");
                break;
            }
        }
        //System.out.println(Wlist);
        return Wlist;
    }

    public ArrayList<String> getWord(){
        return wordCheck();
    }
    public ArrayList<String> Sentence(){
        ArrayList<String> Slist = new ArrayList<>(6);
        for(int i=0;i<6;i++){
            Slist.add(SentenceList[i]);
        }
        //System.out.println(Slist);
        return Slist;
    }

}




// This is the updated Tokenizer class
import java.util.ArrayList;
import java.util.List;

public class Tokenizer {
    Reader rd = new Reader();
    ArrayList<String> SplList = new ArrayList<>();
    public ArrayList<String> splitString() {
        ArrayList<String> Wlist = rd.getWord();
        //String[] result = new String[(Wlist.get().length()+2)/3];
        for(int i=0;i<Wlist.size();i++){
                SplList.add(Arrays.toString(Wlist.get(i).split("(?<=\\\\G..)(?=..)")));

        }

        System.out.println(SplList);
        return SplList;
    }
}

Answer 1

如果您询问如何将字符串拆分为成对的字母，最后一次拆分留下任何剩余部分：

String[] parts = str.split("(?<=\\G..)(?=..)");

这实现了你的目标（见下文）。

这两个环视之间的拆分匹配：

• (?<=\\G..)最后一场比赛结束后的两个字符
• (?=..)之后（至少）有两个字符

---

String[] wordList = {"Printer", "Airport", "Painter", "Letter", "vehicle", "Teacher"};
List<String[]> splitWords = Arrays.stream(wordList).map(s -> s.split("(?<=\\G..)(?=..)")).collect(toList());
splitWords.forEach(a -> System.out.println(Arrays.toString(a)));

Output：

[Pr, in, ter]
[Ai, rp, ort]
[Pa, in, ter]
[Le, tt, er]
[ve, hi, cle]
[Te, ac, her]